In general, in conventional endoscopic examinations using an endoscope, in vivo image data picked up by an endoscopic apparatus or an endoscopic observation apparatus are immediately displayed on a display device such as a CRT and externally stored as motion picture data. A physician views the motion pictures or views frame images in the motion pictures as still images, during or after examinations for diagnosis.
Further, in recent years, swallowable capsule endoscopes have been used.
For example, as disclosed in Japanese Patent Laid-Open No. 2004-645, image data picked up in vivo with an in-capsule endoscope is sequentially externally accumulated as motion picture data by radio communication. The physician views the motion pictures or views frame images in motion pictures as still images for diagnosis.
Furthermore, Japanese Patent Laid-Open No. 2004-188026 discloses an apparatus that applies an image analysis process on still images to display the results of the analysis on endoscopic images or in another display area.
The image analysis results allow the physician to make diagnosis on the basis of image analysis values for IHb, vessel analysis, and the like, which are objective determination criteria, without recourse of the physician's subjective.
However, when the physician views motion pictures after endoscopic examinations or views motion pictures picked up by an in-capsule endoscope, the enormous number of frame images contained in the motion pictures results in the need to make much effort in finding a point on the motion pictures at which a suspected lesion is shown, extracting each frame image showing the lesion and apply an image analysis process to the image, and making diagnosis on the basis of each image analysis result.
To solve this problem, a system can be implemented which uses the above image analysis apparatus for still images to apply the same image analysis process to all the frame images contained in the motion pictures and to then store the results.
However, the application of the same image analysis process to all the frame images increases processing time, resulting in the need to wait a long time until processing results are obtained. Further, a long time is required until appropriate processing results are obtained even if the image analysis process is applied with parameters changed. Another disadvantage is that this method increases the amount of data needing to be stored until appropriate processing results are obtained.
Furthermore, screening in examinations with an endoscopic apparatus determines whether or not the Barrett mucosa or the Barrett esophagus is present. The Barrett mucosa is developed when at the junction between the stomach and the esophagus (EG junction), the squamous epithelium forming the esophagus is replaced with the mucosa of the stomach under the effect of the reflux esophagitis or the like. The Barrett mucosa is also called the cylindrical epithelium. If the Barrett mucosa extends at least 3 cm from the mucosal boundary all along the circumference of a cross section of the lumen of the esophagus, the patient is diagnosed to have a disease called the Barrett esophagus.
The incidence of the Barrett esophagus has been increasing particularly among Americans and Europeans. The Barrett esophagus is very likely to develop into the adenocarcinoma and thus has been a major problem. Consequently, it is very important to discover the Barrett mucosa early.
Thus, medical image processing apparatus are desired to objectively determine biological feature values for the Barrett esophagus, the Barrett mucosa, or the like and to provide determinations to the operator.
Further, as described above, in the medical field, observation and diagnosis of the organs in the body cavity are widely performed using medical equipment having an image pickup function.
For example, in the diagnosis of the esophageal disease, in the case of the disease diagnosis of the Barrett esophagus near the EG junction (junction between the stomach and the esophagus) in the upper part of the cardia, which corresponds to the boundary between the stomach and the esophagus, endoscopic examinations are important for the diagnosis of the esophagus because the Barrett esophagus may develop into the adenocarcinoma as described above. An endoscope is inserted into a patient's mouth, and the physician makes the diagnosis of the esophageal disease while viewing endoscopic images displayed on a monitor screen.
Further, as described above, in recent years, capsule-like endoscopes have been developed which allow the physician to make the diagnosis of the esophageal disease while viewing images obtained with the capsule-like endoscope. A system has been proposed which detects the disease on the basis of biological images obtained with a capsule-like endoscope (see, for example, WO 02/073507 A2).
However, even the above proposed system does not disclose the detection of the cardia or the vicinity of the cardia boundary based on images showing an area extending from the esophagus to the stomach.
For example, enabling the cardia or the boundary of the cardia to be detected allows the physician to observe biological tissue images of the detected cardia or cardia boundary in detail. This enables the disease such as the Barrett esophagus to be quickly diagnosed.